23

#include <algorithm>
#include <iostream>

class cNumber {
protected:
    int _value;
public:
    cNumber(int v = 0) :
        _value{ v } { }

    cNumber operator+(const cNumber& other) {
        cNumber number(other.value() + this->value());
        return number;
    }

    friend std::ostream& operator<<(std::ostream& o, cNumber& n) {
        o << n.value();
        return o;
    }

    virtual int value() const {
        return _value;
    }

};

class cAbsNumber : public cNumber {
public:
    cAbsNumber(int i):
        cNumber(i) { }

    int value() const override {
        if (cNumber::value() < 0)
            return -cNumber::value();
        return cNumber::value();
    }
};

int main() {
    cNumber a(-123);
    cNumber b(7);

    cNumber c = (a + b);

    cAbsNumber d(-100);
    cAbsNumber e(123);

    std::cout << c << "\n";
    std::cout << d << "\n";
    std::cout << e << "\n";
}#include <algorithm>
#include <iostream>

class cNumber {
protected:
    int _value;
public:
    cNumber(int v = 0) :
        _value{ v } { }

    cNumber operator+(const cNumber& other) {
        cNumber number(other.value() + this->value());
        return number;
    }

    friend std::ostream& operator<<(std::ostream& o, cNumber& n) {
        o << n.value();
        return o;
    }

    virtual int value() const {
        return _value;
    }

};

class cAbsNumber : public cNumber {
public:
    cAbsNumber(int i):
        cNumber(i) { }

    int value() const override {
        if (cNumber::value() < 0)
            return -cNumber::value();
        return cNumber::value();
    }
};

int main() {
    cNumber a(-123);
    cNumber b(7);

    cNumber c = (a + b);

    cAbsNumber d(-100);
    cAbsNumber e(123);

    std::cout << c << "\n";
    std::cout << d << "\n";
    std::cout << e << "\n";
}